If they're the zip models (I know one is, but the other one could be the bottom entry, the way that's worded), then it really doesn't matter which way you lie in it, as long as your left shoulder and right knee are by the pull-outs. Personally, I find having my left shoulder by the zip side easiest to get in and out, but that's just me. If one is the bottom entry, then simply push yourself through the slit, sit down, and match up shoulder and knee with the pull-outs when you lie back.
As to hang angle, my personal preference is to have the foot end (whichever you wind up choosing for that) approximately 4" to 8" higher than the head end. I prefer the tension on the suspension to be such as to allow me to turn the ridgeline with thumb and forefinger 90* to 180* with my weight in the hammock. Anything less than 90* gives me shoulder squeeze, and anything more'n 180* winds up with the netting sagging into my face and giving me enough knee hyperextension that my heel on my straight leg (I usually lie in a figure-4 position) will hurt come morning.
YMMV, but that's what works for me for maximum comfort. Play with it and see what you prefer; everyone's a little different.
If you want to try out a ring/strap or cinch buckle/strap suspension rather than the stock, you can do so without cutting your line or swapping it out for anything else. Just use the Hennessy lashing to attach to the rings or cinch buckle with the stock line and then hank the rest to keep it from dragging on the ground. I've had 50+ nights with that, except that when I decided to move over to the other suspension, I cut the excess line off (which was a weight decision, not because it interfered with anything).
Hope it helps!